Count of received frames discarded because the frame control character was incorrect. This may indicate that the other side of the link is configured for a different link level protocol. This is a 32-bit read-only Counter32, so it only ever increases while the Passport is running and rolls back over to 0 once it wraps -- a monitoring system should poll it periodically and alert on the rate of increase (deltas), not on the raw value, since a rising rate is what signals a real, ongoing problem rather than a one-off event.